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LakeQuality

Simpson Park Lake Water Temperature

Simpson Park Lake in St. Louis County, Missouri averages about 84°F at the surface in summer — warmest in Aug (~85°F) and coldest in Apr (~66°F). These are typical values by month, not a live reading.

Typical in July
84°F
Warm
Summer average
84°F
Warmest (Aug)
85°F
Coldest (Apr)
66°F

Typical water temperature by month

Jan
Feb
Mar
Apr
66°
May
72°
Jun
83°
Jul
84°
Aug
85°
Sep
80°
Oct
Nov
Dec

Typical surface water temperature by month, from 50 field readings (20102024) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Simpson Park Lake warm enough to swim?

At its summer peak (~84°F): Warm

Very comfortable for swimming. Warm surface water can also favor blue-green algae in nutrient-rich lakes, so check for advisories before you go in.

Want more than temperature? Simpson Park Lake scored D on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.

Where to stay near Simpson Park Lake

Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Simpson Park Lake — live availability and prices.

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Frequently asked questions

What is the water temperature of Simpson Park Lake?

Simpson Park Lake has a typical summer surface temperature of about 84°F. It is usually warmest in August (around 85°F) and coldest in April (around 66°F). These are typical values by month from 50 EPA Water Quality Portal field readings (2010–2024), not a live reading.

When is Simpson Park Lake warmest?

Surface water at Simpson Park Lake is typically warmest in August, reaching about 85°F. Lake surface temperature lags air temperature by several weeks, so the warmest water usually arrives in mid-to-late summer even though the hottest air can come earlier.

Is Simpson Park Lake warm enough to swim?

At its typical summer peak of about 84°F, Simpson Park Lake rates as "warm" for swimming. Very comfortable for swimming. Warm surface water can also favor blue-green algae in nutrient-rich lakes, so check for advisories before you go in.

Where does this Simpson Park Lake water temperature data come from?

Every temperature on this page is a typical (climatological) value computed from real surface-water field readings collected by state and federal agencies and published through the EPA Water Quality Portal — 50 readings from 1 monitoring station between 2010 and 2024. They describe what is typical for each month, not the temperature right now.

About this data

Water temperatures are a climatology — the typical value for each month, averaged from real surface-water field readings collected by state and federal agencies and published through the EPA Water Quality Portal. They tell you what to expect, not the temperature at this moment. Actual conditions vary with recent weather, depth, and time of day.